1. Field of the Invention
The present invention relates to an electronic percussion instrument and a percussion tone control program, and more particularly to an electronic percussion instrument and a percussion tone control program that optimize generation of percussion tones for roll performance.
2. Description of the Related Art
Conventionally, there have been proposed various techniques for optimally dressing musical tones electronically produced by an electronic percussion instrument, or more specifically, various techniques for approximating percussion tones electronically produced by an electronic percussion instrument to percussion tones acoustically produced by a natural percussion instrument.
Japanese Laid-Open Patent Publication (Kokai) No. H05-80754 discloses an electronic percussion instrument which is capable of automatically applying sound effects to enhance a performer's expressive power. According to the publication, when it is detected that tone generation instruction information responsive to percussion applied to a drum pad has been consecutively given within a predetermined time period, the electronic percussion instrument adds a predetermined sounding effect, such as pan, to a musical tone signal generated in response to the tone generation instruction information.
Japanese Laid-Open Patent Publication (Kokai) No. H05-100680 discloses a technique for optimizing generation of musical tones (percussion tones) during repeated beating performance by an electronic percussion instrument. The electronic percussion instrument described in the publication stores a pair of waveform data for normal performance and waveform data for repeated beating performance, on a pad-by-pad basis. When a beat is applied to one pad, a time interval between the beat and an immediately preceding beat applied to the pad is detected, and if the detected time interval is shorter than a predetermined value, a musical tone signal indicative of the associated percussion tone is generated using the waveform data for repeated beating performance. More specifically, the electronic percussion instrument stores two types of waveform data as a pair on a pad-by-pad basis, and when percussion is applied to one pad within a predetermined time period, waveform data used for producing a musical tone signal for each beat is switched between one beat and the following beat, as deemed appropriate.
Performance methods realized by repeatedly beating a percussion instrument include flam performance and roll performance. In flam performance, a single beat by each of left and right sticks is applied with a short stroke, whereas in roll performance, a plurality of short-stroke beats by each of the left and right sticks are consecutively applied over a certain time period. When a natural percussion instrument is played according to these two performance methods, a clear difference in tone color appears between the percussion tones produced by the respective performance methods. Therefore, to approximate a percussion tone electronically produced by an electronic percussion instrument to a percussion tone acoustically produced by a natural percussion instrument, it is desirable that roll performance and flam performance should be accurately distinguished from each other such that a specific musical tone signal can be generated by each of the performance methods.
However, in the technique described in Japanese Laid-Open Patent Publication (Kokai) No. H05-100680, one of the two types of waveform data is selectively used only based on whether or not a time interval between two consecutive beats is shorter than a predetermined value, and hence it is impossible to distinguish roll performance from flam performance for which waveform data different from that used for roll performance should preferably be used.
Further, in the conventional electronic percussion instrument in which switching of waveform data is performed only based on whether a time interval from an immediately preceding beat is within a predetermined value, when application of a beat within the predetermined time interval from an immediately preceding beat occurs a plurality of consecutive times, musical tone signals in a number corresponding to that of the succeeding beats are simply generated based on the same waveform data, which can give an impression that the performance is monotonous.